Abstract: Provided is a method for manufacturing a group III nitride semiconductor substrate includes a substrate preparation step S10 of preparing a sapphire substrate, a heat treatment step S20 of performing a heat treatment on the sapphire substrate, a pre-flow step S30 of supplying a metal-containing gas over the sapphire substrate, a buffer layer forming step S40 of forming a buffer layer over the sapphire substrate under growth conditions of a growth temperature of 800° C. or higher and 950° C. or lower and a pressure of 30 torr or more and 200 torr or less, and a growth step S50 of forming a group III nitride semiconductor layer over the buffer layer under growth conditions of a growth temperature of 800° C. or higher and 1025° C. or lower, a pressure of 30 torr or more and 200 torr or less, and a growth speed of 10 ?m/h or more.

Abstract: A method for manufacturing a group III nitride semiconductor substrate includes a sapphire substrate preparation step S10 for preparing a sapphire substrate having, as a main surface, a {10-10} plane or a plane obtained by inclining the {10-10} plane at a predetermined angle in a predetermined direction; a heat treatment step S20 for performing a heat treatment over the sapphire substrate while performing a nitriding treatment or without performing the nitriding treatment; a buffer layer forming step S30 for forming a buffer layer over the main surface of the sapphire substrate after the heat treatment; and a growth step S40 for forming a group III nitride semiconductor layer, in which a growth surface has a predetermined plane orientation, over the buffer layer, in which at least one of a plane orientation of the main surface of the sapphire substrate, presence or absence of the nitriding treatment during the heat treatment, and a growth temperature in the buffer layer forming step is adjusted such that the

Abstract: A method for manufacturing a group III nitride semiconductor substrate includes a preparation step S10 for preparing a group III nitride semiconductor substrate having a sapphire substrate having a semipolar plane as a main surface, and a group III nitride semiconductor layer positioned over the main surface, in which a <0002> direction of the sapphire substrate and a <10-10> direction of the group III nitride semiconductor layer do not intersect at right angles in a plan view in a direction perpendicular to the main surface, and a growth step S20 for epitaxially growing a group III nitride semiconductor over the group III nitride semiconductor layer.

Abstract: A method for manufacturing a group III nitride semiconductor substrate includes a sapphire substrate preparation step S10 for preparing a sapphire substrate having, as a main surface, a {10-10} plane or a plane obtained by inclining the {10-10} plane at a predetermined angle in a predetermined direction; a heat treatment step S20 for performing a heat treatment over the sapphire substrate while performing a nitriding treatment or without performing the nitriding treatment; a buffer layer forming step S30 for forming a buffer layer over the main surface of the sapphire substrate after the heat treatment; and a growth step S40 for forming a group III nitride semiconductor layer, in which a growth surface has a predetermined plane orientation, over the buffer layer, in which at least one of a plane orientation of the main surface of the sapphire substrate, presence or absence of the nitriding treatment during the heat treatment, and a growth temperature in the buffer layer forming step is adjusted such that the

Abstract: A method for manufacturing a group III nitride semiconductor substrate includes a preparation step S10 for preparing a group III nitride semiconductor substrate having a sapphire substrate having a semipolar plane as a main surface, and a group III nitride semiconductor layer positioned over the main surface, in which a <0002> direction of the sapphire substrate and a <10-10> direction of the group III nitride semiconductor layer do not intersect at right angles in a plan view in a direction perpendicular to the main surface, and a growth step S20 for epitaxially growing a group III nitride semiconductor over the group III nitride semiconductor layer.